1. Field of the Invention
The present invention relates to multi-lumen catheters, more particularly, to a multi-lumen catheter capable of measuring cardiac output continuously, mixed venous oxygen saturation as well as other hemodynamic parameters. The catheter is also capable of undertaking therapeutic operations such as drug infusion and cardiac pacing.
2. Description of the Prior Art
As is well known, catheters have been developed for purposes of measuring various specific hemodynamic parameters, such as blood pressure, cardiac output, right heart ejection fraction, and mixed venous oxygen saturation, as well as to infuse medication, withdraw blood or to pace the heart.
Cardiac catheters having flotation balloons and which measure cardiac output using the bolus thermodilution technique are well known in the art, as disclosed for example in U.S. Pat. No. 4,508,123, to Wyatt et al. Additionally, catheters having optical fibers connected to light emitting and receiving means and to signal processing/displaying means have been used to measure oxygen saturation in blood (i.e. SvO2), as disclosed in U.S. Pat. No. 4,651,741 to Passafaro. More recently, catheters have been designed with resistance heaters for the purpose of monitoring cardiac output on a continuous basis. An example of such a catheter is disclosed in U.S. patent application Ser. No. 08/049,231, to Quinn et al.
To date, however, no one has designed a catheter that is capable of measuring the aforementioned hemodynamic parameters without having to remove and reinsert multiple catheters and probes. Specifically, no one has designed a flotation balloon catheter having a resistance heater and a lumen for housing optical fibers to measure cardiac output continuously and to measure mixed venous oxygen saturation.